Azo-dyestuffs and their manufacture



Patented Aug. 25, 1936 UNITED STATES AZO-DYESTUFFS AND THEIR MANUFACTUREAdolf Krebser, Riehen, near Basel, Switzerland,

asslgnor to the firm J.

Switzerland It. Geigy A. G., Basel,

No Drawing. Application October 16, 1935, Serial No. 45,358. InSwitzerland November 5, 1934 12 Claims.

This invention consists in the manufacture of new valuablemonoazo-dyestufis capable of being chromed by coupling thediazo-compound from 4-nitro-2-amino-phenol-G-sulphonic acid with aphenol containing in para-position an alkyl-group with at least 3 and atmost carbon atoms.

The new dyestuffs are dark powders and dye wool in an acid bathyellow-brown tints. When chromed these tints change to a valuable fullbrown with excellent properties of fastness. The dyestuffs may also beconverted into the chromium complex before their application in thedyeing process.

The following examples illustrate the invention:

Example 1 23.4. kilos of 4-nitro-2-aminophenol-6-sulphonic acid arediazotized by the usual method. The excess of mineral acid is bufferedby means of sodium bicarbonate and the diazonium solution is added,while stirring, to a solution of 16.5 kilos of para-tertiary-amyl-phenolin 6 kilos of caustic potash lye of 100 per cent strength and 50 litresof water. When coupling is complete the dyestuff is salted out, filteredand dried. The formation of the dyestuif can be facilitated by thepresence of pyridine.

The dyestufi is a brown powder soluble in water and in concentratedsulphuric acid to yellowbrown solutions.

If in this example para-tertiary-amyl-orthocresol is used as couplingcomponent, a dyestuif with similar properties is obtained. F

Ewample 2 For the quantity of para-tertiary-amyl-phenol used forcoupling in Example 1 there is substituted 13.5 kilos of para-isoornormal-propylphenol or 15 kilos of para-tertiary-butyl-phenol, orpara-isobutyl-ortho-cresol, the quantity of the diazonium solution beingthe same as prescribed in Example 1; there are obtained brownchromedyestuffs with similar excellent properties of fastness.

What I claim is:--

1. A process for the manufacture of azo-dyestuffs, consisting incoupling diazotized 4-nitro- 2-aminophenol-6-sulphonic acid with amonocycle phenol containing as a substituent in paraposition analkyl-group with at least 3 and at most 5 carbon atoms.

2. A process for the manufacture of azo-dyestuffs, consisting incoupling diazotized 4-nitro- Z-aminophenol-fi-sulphonic acid in thepresence of pyridine with a monocyclic phenol containing as asubstituent in para-position an alkyl-group with at least 3 and at most5 carbon atoms.

3. A process for the manufacture of azo-dyestuffs, consisting incoupling diazotized l-nitro- 2-aminophenol-S-sulphonic acid with amonocyclic phenol containing as a substituent in paraposition analkyl-group with 3 carbon atoms.

4. A process for the manufacture of azo-dyestufis, consisting incoupling diazotized 4-nitr0- Z-aminophenol-G-sulphonic acid with amonocyclic phenol containing as a substituent in paraposition analkyl-group with 4 carbon atoms.

5. A process for the manufacture of azo-dyestuifs, consisting incoupling diazotized l-nitro- Z-aminophenol-fi-sulphonic acid with amonocyclic phenol containing as a substituent in paraposition analkyl-group with 5 carbon atoms.

6. A process for the manufacture of azo-dyestuifs, consisting incoupling diazotized 4-nitro- 2-aminophenol-6-sulphonic acid in thepresence of pyridine with a monocyclic phenol containing as asubstituent in para-position an alkylgroup with 3 carbon atoms.

7. A process for the manufacture of azo-dyestuifs, consisting incoupling diazotized 4-nitro- Z-aminophenol-G-sulphonic acid in thepresence of pyridine with as a substituent in para-position analkyl-group with 4 carbon atoms.

8. A process for the manufacture of azo-dyestufis, consisting incoupling diazotized 4-nitro- Z-aminophenol-S-sulphonic acid in thepresence of pyridine with a monocyclic phenol containing as asubstituent in para-position an alkyl-group with 5 carbon atoms. q

9. A process for the manufacture of an emdyestuif, consisting incoupling diazotized 4- nitro-2-aminophenol-6-sulphonic acid withparatertiary-amyl-phenol.

10. A process for the manufacture of an azodyestufi, consisting incoupling diazotized 4- nitro-2-aminophenol-G-sulphonic acid withpara-isobutyl-o-cresol.

11. A process for the manufacture of an azodyestuif, consisting incoupling diazotized 4- nitro-Z-aminophenol-6-sulphonic acid withgara-isobutyl-o-cresol in the presence of pyri- 12. Azo-dyestuifs fromdiazotized 4-nitro-2- aminophenol-G-sulphonic acid and a monocyclicphenol containing as a substituent in para-position an alkyl-group withat least 3 and at most 5 carbon atoms, said dyestuffs being soluble inwater and in concentrated sulphuric acid to yellow-brown solutions anddyeing wool in an acid bath yellow-brown tints which when chromed becomea valuable full brown of excellent properties of fastness.

ADOLF ICREBSER.

a monocyclic phenol containing

